1. Field of the Invention
Methods and apparatuses consistent with the present invention relate to a method and apparatus for the selection of a Digital Subscriber Line scheme from among all Digital Subscriber Line schemes, profiles, and combinations, collectively referred to as xDSL; implementation of filtering and other signal enhancements of an xDSL signal, and universal demarcation physical interconnect of xDSL within all common Network Interface Devices (NIDs).
2. Description of the Related Art
ITU-T G.993.2 (02/2006) (Series G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS—Very high speed digital subscriber line transceivers 2 (VDSL2)) discloses an access technology that exploits the communication infrastructure deployed for plain-old telephone service (POTS) systems. In particular, ITU-T G.993.2 discloses a data delivery scheme within the POTS system which includes eight (8) VDSL2 profiles.
Other related publications and standards include ITU-T G.992.1 Asymmetric Digital Subscriber Line (ADSL); ITU-T G.992.3 Improved Standardization of ADSL (ADSL2); ITU-T G.992.5 Extension of ADSL2 With Double Bandwidth (ADSL2+); ITU-T G.993.1 Very High Speed Digital Subscriber Line (VDSL); ITU-T G.991.2 Symmetric High Speed DSL (SHDSL). ITU-T G.993.2, G.992.1, G.992.3, G.992.5, G.993.1, and G.991.2, are hereby incorporated by reference in its entirety.
Collectively these data transmission methods have come to be known, and are referred to as xDSL. xDSL profiles relate to specific frequency plans, power spectral density (PSD), modulation schemes, noise mitigation techniques and data rates for transmission of data within a POTS system employing an unshielded twisted pair wire (UTP), but are not limited to this transmission medium and are, on occasion, deployed using coaxial cable (COAX), multi-pair Ethernet cable or a combination of media.
Key to the successful operation of an xDSL system is a splitter composed of a conventional low pass voice-band filter and a high pass or band pass data filter matched to the specific xDSL profile employed by the system. Other signal enhancement, noise mitigation and signal conversion techniques are also employed within the splitter. A base module and an add-on module; collectively also referred to as a splitter-filter or splitter-filter-balun; are typically located within a Network Interface Device (NID) which may be located at the premise demarcation point where, in general, the telephone line enters the premise, or at a wall plate or other location within the premise.
The NID is a physical box, or enclosure, commonly located outside of a residence or building in close proximity to where the telephone line(s) from the Telephone Companies Central Office (CO) interconnects with the residence or buildings internal communications wiring. This interconnect point forms what is often referred to as “the demarcation point.” As such, the demarcation point is often at the physical NID. However, a Multi Dwelling Unit (MDU) for example might have a distribution panel within a common communications room on the ground floor with the demarcation point being located at a Wall Plate within each unit.
Within each NID enclosure a method is required to facilitate the physical inter-connection of the CO UTP, COAX, or other transmission media with the premise's hard wiring or other transmission media. A module with attached interconnect apparatus, typically screw terminals, is secured within the NID to accomplish the interconnection.
xDSL splitter, filter and signal conditioning devices may also be located at the NID interconnect point. Over the years a variety of NID enclosures have been fielded; with each model having differing physical configurations and orientations and, as such, require current art xDSL devices to take a form that will only fit within a specific model NID; therefore a very large number of physically different xDSL devices must be created for each xDSL profile and each of these devices must have several versions to support their associated enhancement modules. Thus creating a large number of physically different xDSL devices is required to support the many NID installations and types that are currently deployed in the field.
Conventional Splitter-filters are only matched to one xDSL profile, are constructed as a single fixed dual slot unit, and can not accommodate reconfigurations or add-on enhancements. Thus, as the xDSL system develops, or is modified to use a second xDSL profile, conventional splitters must be physically replaced with a second conventional splitter, with the second conventional splitter matched to the second xDSL profile. The need for multiple xDSL splitters, each matched to a specific xDSL profile, as well as the physical installation required each time an xDSL profile is changed; increases the cost of operating and maintaining the xDSL system.
Furthermore, conventional splitter-filter modules require two adjacent slots to fit within any NID. The package enclosing multiple filter modules is large overall and, as such, the number of remaining available slots for future expansion within a NID is reduced.
Conventional technology does not provide means for feature set expansion or customization as part of the splitter-filter module. For example; a balanced two (2) wire differential circuit conversion to an unbalanced coaxial single-ended circuit would require a complete new device. Conventional technology is either a stand alone splitter-filter module or a combination splitter-filter-balun module. They are not field upgradeable and must be replaced at considerable expense both in parts and skilled labor if, for example, the profile filtering or output connectivity required adjustment, re-configuration or replacement.
The vast majority of conventional splitter-filter modules currently used today employ screw terminals to make connections between the network and the premise or buildings internal wiring requiring special tools, extra labor by skilled technicians and occupying excess space within the NID.
Conventional technology requires a unique and separate form factor package for each type of currently available NID enclosure deployed in the US market today. These styles are commonly referred to as the Sekor (“S”) and Keptel (“K”) type NID; with each model type footprint mount interface being different, and there is little or no physical commonality between the two styles; therefore each type and model requires an interconnect scheme and splitter module of different physical shape
Conventional art splitter modules do not provide a means of attaching auxiliary modules or brackets, as may be required for the addition of associated hardware, mechanical network system customization, security features and their fit and form factor can not be mounted in both flat bottomed, recessed well, or pocket NID enclosures.
Conventional splitter devices are not mechanically or electrically modular in nature, thus do not accommodate field configuration of xDSL profile filtering, system enhancements or variations in interconnect while still remaining in one single line space footprint. Conventional splitters do not provide an add-on means to use alternate connector types other than several specific splitter modules have been developed that employ the coaxial “F” connector style.
Specifically; the use of existing technology would require AT&T to replace all installed 3-line space NIDs in the entire AT&T/BellSouth region to complete their on-going VDSL2 (Project Lightspeed) Deployment.